Confocal microscopy is an optical technique commonly used to obtain detailed information about cells, tissues, microbial biofilms, and colloidal glasses. A confocal microscope typically includes an objective lens proximate a sample and a focusing lens proximate a screen with a pinhole. The confocal microscope collects in-focus light signals from the sample through the pinhole. As a result, out-of-focus signals are eliminated. As only light signals produced at and/or close to the focal plane of the objective lens can be detected, the image's optical resolution is much better than that of wide-field microscopes.